We propose to assess the validity of a blunted and discordant affect (BADA) construct in multiply- symptomatic pan-diagnostic individuals stratified on abuse history and diagnosis, compared to healthy individuals. Common treatments for depression, anxiety, Post-Traumatic Stress Disorder (PTSD), and Borderline personality disorder (BPD), which are typically effective for up to 40-60% of patients, work to reduce high affective intensity and reactivity, e.g., hyperarousal, irritability, or threat sensitivity. The opposite pole, involving blunted and discordant affective responses, is frequently described by clinicians, e.g., as shutting down, but is rarely researched, and is not as explicitly addressed in common treatments. Clinicians particularly note these features in survivors of chronic childhood abuse, who often have affective psychopathologies. Improved understanding of this construct, including its prevalence, mechanisms, and differentiation from affective hyper-reactivity, could lead to specialized and effective treatment for individuals characterized by it. We will examine this construct via affect-rating, physiological, and neuroimaging during conventional tasks and tasks that approximate conditions in which functional deficits are observed in 150 patients with depression, anxiety, PTSD, and Borderline Personality Disorder as well as 50 healthy participants. Primary aims, will be to examine: 1) Construct validity-the magnitude, time course, and neural mechanisms of blunted and discordant affect, 2) Concurrent validity-relationships of the assessed measures of blunted and discordant affect with self-reported trait coping and affect constructs such as such as dissociation, numbing, repression, suppression, distraction, avoidance, and discordant attachment. This aim puts the construct in the context of the broader similar literature, and 3) External validity-specificity of observed constructs with respect to abuse history, diagnostic category, hyper-reactivity, valence, and functioning. This aim characterizes the generalizability of the construct with regard to whether it is a dimension or syndrome, trauma history, axis I and II diagnoses, valence specificity, and functioning. Positive results could suggest it is necessary to abandon the practice of averaging self-report, physiological, and neuroimaging data across patients and instead assess both hyper- and hypo-reactivity as important to psychopathology. Next steps would entail examining whether these poles are differentially associated with treatment outcome in conventional treatments and development of treatments to target both hyper- and hypo-reactivity. PUBLIC HEALTH RELEVANCE: Common mechanistic theories of and treatments for depression and anxiety disorders regard hyper-reactivity to emotional information. We propose to show that the opposite poles, blunted emotional responses, are common and clinically meaningful. We further propose to show that this phenomenon is related to early traumatic experiences. Positive results would suggest that averaging data across patients with a disorder is misleading as increased and decreased reactions could average out to hide problems on both sides of the spectrum. Rather, we will demonstrate methods for more sensitive assessments of this phenomenon.